# GitLab.com settings In this page you will find information about the settings that are used on [GitLab.com](https://about.gitlab.com/pricing). ## SSH host keys fingerprints Below are the fingerprints for GitLab.com's SSH host keys. | Algorithm | MD5 | SHA256 | | --------- | --- | ------- | | DSA | `7a:47:81:3a:ee:89:89:64:33:ca:44:52:3d:30:d4:87` | `p8vZBUOR0XQz6sYiaWSMLmh0t9i8srqYKool/Xfdfqw` | | ECDSA | `f1:d0:fb:46:73:7a:70:92:5a:ab:5d:ef:43:e2:1c:35` | `HbW3g8zUjNSksFbqTiUWPWg2Bq1x8xdGUrliXFzSnUw` | | ED25519 | `2e:65:6a:c8:cf:bf:b2:8b:9a:bd:6d:9f:11:5c:12:16` | `eUXGGm1YGsMAS7vkcx6JOJdOGHPem5gQp4taiCfCLB8` | | RSA | `b6:03:0e:39:97:9e:d0:e7:24:ce:a3:77:3e:01:42:09` | `ROQFvPThGrW4RuWLoL9tq9I9zJ42fK4XywyRtbOz/EQ` | ## Mail configuration GitLab.com sends emails from the `mg.gitlab.com` domain via [Mailgun] and has its own dedicated IP address (`198.61.254.240`). ## Alternative SSH port GitLab.com can be reached via a [different SSH port][altssh] for `git+ssh`. | Setting | Value | | --------- | ------------------- | | `Hostname` | `altssh.gitlab.com` | | `Port` | `443` | An example `~/.ssh/config` is the following: ``` Host gitlab.com Hostname altssh.gitlab.com User git Port 443 PreferredAuthentications publickey IdentityFile ~/.ssh/gitlab ``` ## GitLab Pages Below are the settings for [GitLab Pages]. | Setting | GitLab.com | Default | | ----------------------- | ---------------- | ------------- | | Domain name | `gitlab.io` | - | | IP address | `52.167.214.135` | - | | Custom domains support | yes | no | | TLS certificates support| yes | no | The maximum size of your Pages site is regulated by the artifacts maximum size which is part of [GitLab CI/CD](#gitlab-ci-cd). ## GitLab CI/CD Below are the current settings regarding [GitLab CI/CD](../../ci/README.md). | Setting | GitLab.com | Default | | ----------- | ----------------- | ------------- | | Artifacts maximum size | 1G | 100M | ## Repository size limit The maximum size your Git repository is allowed to be including LFS. | Setting | GitLab.com | Default | | ----------- | ----------------- | ------------- | | Repository size including LFS | 10G | Unlimited | ## Shared Runners Shared Runners on GitLab.com run in [autoscale mode] and powered by DigitalOcean. Autoscaling means reduced waiting times to spin up builds, and isolated VMs for each project, thus maximizing security. They're free to use for public open source projects and limited to 2000 CI minutes per month per group for private projects. Read about all [GitLab.com plans](https://about.gitlab.com/pricing/). All your builds run on 2GB (RAM) ephemeral instances, with CoreOS and the latest Docker Engine installed. The default region of the VMs is NYC. Below are the shared Runners settings. | Setting | GitLab.com | Default | | ----------- | ----------------- | ---------- | | [GitLab Runner] | [Runner versions dashboard][ci_version_dashboard] | - | | Executor | `docker+machine` | - | | Default Docker image | `ruby:2.1` | - | | `privileged` (run [Docker in Docker]) | `true` | `false` | [ci_version_dashboard]: https://monitor.gitlab.net/dashboard/db/ci?refresh=5m&orgId=1&panelId=12&fullscreen&from=now-1h&to=now&var-runner_type=All&var-cache_server=All&var-gl_monitor_fqdn=postgres-01.db.prd.gitlab.com&var-has_minutes=yes&var-hanging_droplets_cleaner=All&var-droplet_zero_machines_cleaner=All&var-runner_job_failure_reason=All&theme=light ### `config.toml` The full contents of our `config.toml` are: ```toml [[runners]] name = "docker-auto-scale" limit = X request_concurrency = X url = "https://gitlab.com/ci" token = "SHARED_RUNNER_TOKEN" executor = "docker+machine" environment = [ "DOCKER_DRIVER=overlay2" ] [runners.docker] image = "ruby:2.1" privileged = true [runners.machine] IdleCount = 40 IdleTime = 1800 MaxBuilds = 1 MachineDriver = "digitalocean" MachineName = "machine-%s-digital-ocean-2gb" MachineOptions = [ "digitalocean-image=coreos-stable", "digitalocean-ssh-user=core", "digitalocean-access-token=DIGITAL_OCEAN_ACCESS_TOKEN", "digitalocean-region=nyc1", "digitalocean-size=2gb", "digitalocean-private-networking", "digitalocean-userdata=/etc/gitlab-runner/cloudinit.sh", "engine-registry-mirror=http://IP_TO_OUR_REGISTRY_MIRROR" ] [runners.cache] Type = "s3" ServerAddress = "IP_TO_OUR_CACHE_SERVER" AccessKey = "ACCESS_KEY" SecretKey = "ACCESS_SECRET_KEY" BucketName = "runner" Shared = true ``` ## Sidekiq GitLab.com runs [Sidekiq][sidekiq] with arguments `--timeout=4 --concurrency=4` and the following environment variables: | Setting | GitLab.com | Default | |-------- |----------- |-------- | | `SIDEKIQ_MEMORY_KILLER_MAX_RSS` | `1000000` | `1000000` | | `SIDEKIQ_MEMORY_KILLER_SHUTDOWN_SIGNAL` | `SIGKILL` | - | | `SIDEKIQ_LOG_ARGUMENTS` | `1` | - | ## Cron jobs Periodically executed jobs by Sidekiq, to self-heal Gitlab, do external synchronizations, run scheduled pipelines, etc.: | Setting | GitLab.com | Default | |-------- |------------- |------------- | | `pipeline_schedule_worker` | `19 * * * *` | `19 * * * *` | ## PostgreSQL GitLab.com being a fairly large installation of GitLab means we have changed various PostgreSQL settings to better suit our needs. For example, we use streaming replication and servers in hot-standby mode to balance queries across different database servers. The list of GitLab.com specific settings (and their defaults) is as follows: | Setting | GitLab.com | Default | |:------------------------------------|:--------------------------------------------------------------------|:--------------------------------------| | archive_command | `/usr/bin/envdir /etc/wal-e.d/env /opt/wal-e/bin/wal-e wal-push %p` | empty | | archive_mode | on | off | | autovacuum_analyze_scale_factor | 0.01 | 0.01 | | autovacuum_max_workers | 6 | 3 | | autovacuum_vacuum_cost_limit | 1000 | -1 | | autovacuum_vacuum_scale_factor | 0.01 | 0.02 | | checkpoint_completion_target | 0.7 | 0.9 | | checkpoint_segments | 32 | 10 | | effective_cache_size | 338688MB | Based on how much memory is available | | hot_standby | on | off | | hot_standby_feedback | on | off | | log_autovacuum_min_duration | 0 | -1 | | log_checkpoints | on | off | | log_line_prefix | `%t [%p]: [%l-1] ` | empty | | log_min_duration_statement | 1000 | -1 | | log_temp_files | 0 | -1 | | maintenance_work_mem | 2048MB | 16 MB | | max_replication_slots | 5 | 0 | | max_wal_senders | 32 | 0 | | max_wal_size | 5GB | 1GB | | shared_buffers | 112896MB | Based on how much memory is available | | shared_preload_libraries | pg_stat_statements | empty | | shmall | 30146560 | Based on the server's capabilities | | shmmax | 123480309760 | Based on the server's capabilities | | wal_buffers | 16MB | -1 | | wal_keep_segments | 512 | 10 | | wal_level | replica | minimal | | statement_timeout | 15s | 60s | | idle_in_transaction_session_timeout | 60s | 60s | Some of these settings are in the process being adjusted. For example, the value for `shared_buffers` is quite high and as such we are looking into adjusting it. More information on this particular change can be found at . An up to date list of proposed changes can be found at . ## Unicorn GitLab.com adjusts the memory limits for the [unicorn-worker-killer][unicorn-worker-killer] gem. Base default: * `memory_limit_min` = 750MiB * `memory_limit_max` = 1024MiB Web front-ends: * `memory_limit_min` = 1024MiB * `memory_limit_max` = 1280MiB ## GitLab.com at scale In addition to the GitLab Enterprise Edition Omnibus install, GitLab.com uses the following applications and settings to achieve scale. All settings are located publicly available [chef cookbooks](https://gitlab.com/gitlab-cookbooks). ### ELK We use Elasticsearch, logstash, and Kibana for part of our monitoring solution: - [gitlab-cookbooks / gitlab-elk · GitLab](https://gitlab.com/gitlab-cookbooks/gitlab-elk) - [gitlab-cookbooks / gitlab_elasticsearch · GitLab](https://gitlab.com/gitlab-cookbooks/gitlab_elasticsearch) ### Prometheus Prometheus complete our monitoring stack: - [gitlab-cookbooks / gitlab-prometheus · GitLab](https://gitlab.com/gitlab-cookbooks/gitlab-prometheus) ### Grafana For the visualization of monitoring data: - [gitlab-cookbooks / gitlab-grafana · GitLab](https://gitlab.com/gitlab-cookbooks/gitlab-grafana) ### Sentry Open source error tracking: - [gitlab-cookbooks / gitlab-sentry · GitLab](https://gitlab.com/gitlab-cookbooks/gitlab-sentry) ### Consul Service discovery: - [gitlab-cookbooks / gitlab_consul · GitLab](https://gitlab.com/gitlab-cookbooks/gitlab_consul) ### Haproxy High Performance TCP/HTTP Load Balancer: - [gitlab-cookbooks / gitlab-haproxy · GitLab](https://gitlab.com/gitlab-cookbooks/gitlab-haproxy) [autoscale mode]: https://docs.gitlab.com/runner/configuration/autoscale.html "How Autoscale works" [runners-post]: https://about.gitlab.com/2016/04/05/shared-runners/ "Shared Runners on GitLab.com" [GitLab Runner]: https://gitlab.com/gitlab-org/gitlab-runner [altssh]: https://about.gitlab.com/2016/02/18/gitlab-dot-com-now-supports-an-alternate-git-plus-ssh-port/ "GitLab.com now supports an alternate git+ssh port" [GitLab Pages]: https://about.gitlab.com/features/pages "GitLab Pages" [docker in docker]: https://hub.docker.com/_/docker/ "Docker in Docker at DockerHub" [mailgun]: https://www.mailgun.com/ "Mailgun website" [sidekiq]: http://sidekiq.org/ "Sidekiq website" [unicorn-worker-killer]: https://rubygems.org/gems/unicorn-worker-killer "unicorn-worker-killer"